Again, WHO IS TO BLAME? You ASSUMED that it would work. You should have asked anywhere before you bought it. It's Lexmark's decision to support whoever they want.
BTW, as far as support for hardware, consider that I had a NetTV-98 card that worked fine under Linux. Mind you, this was a card that was solely supported under Windows 98. There are NO drivers for XP for this card, and it managed to BSOD my XP machine. So much for Windows being able to detect everything, eh? Then again, the card manufacturer never said it would work with Windows XP.
I understand your frustration, but just chalk it up to experience. I have various computers running OS X, Mac OS Classic, Windows XP, and Linux. They all work flawlessly for me, but every so often i'll encounter some incompatibility. There's nothing you can do, and bitching about it won't help....especially if you're going to bash something that many users of this Mac OS forum have not had problems with. You'll come off sounding like a troll and won't get any help from anyone. The best they'll tell you is to sell the Mac and continue to use your PC.
And you're not screwed. Your router will work with the Mac. I have a Linksys WRT54G and I have my iMac G4 running OS X 10.4.6, my Quadra 650 running System 7.6.1, my Linux PC running Slackware, and my Windows box all connected to it. Both the iMac and the Windows box are wireless. All of them can print to the printers (HP, since my experience tells me they work on all three platforms) and all of them can file share (for the most part...the Quadra only talks to the Linux box through netatalk and the iMac). And yes, all of them can get on the Internet. So rest assured it will work.
Just quit venting and help us find a solution for you that will work.